495 



the simplest forms of animal life, or with the embryo of the higher 

 animals, it may be very difficult to say at what point intelligence 

 begins to manifest itself; our attention is concentrated, therefore, 

 upon those functions which appear to be the result of purely me- 

 chanical arrangements, acted upon by external stimuli. The 

 animal becomes to our perception an automaton, and in fact, by 

 excising some of the nervous organs last developed in its growth, 

 we can render an adult animal an automaton, capable of perform- 

 ing only those habitual actions to which its brain, when in perfect 

 condition, had educated the muscles of voluntary motion. On the 

 other hand, commencing with the highest group in each type, and 

 going downwards, either in structural complication, or in age of 

 individual, it is impossible to fix the limit at which intelligence 

 ceases to be apparent. 



I have in this subject, as in that of tracing the past history of 

 our insects, in the first part of this address, preferred the latter 

 mode of investigation ; taking those things which are nearest to us 



The second consideration is, since it is so difficult for us to un- 

 derstand the mental processes, whether rational or instinctive (I 

 care not by what name they are called), of beings more or less 

 similar, but inferior to ourselves ; we should exercise great caution 

 when we have occasion to speak of the designs of One who is in- 

 finitely greater. Let us give no place to the crude speculations of 

 would-be-teleologists, who are indeed, in great part refuted already 

 by the progress of science, which continually exhibits to us higher 

 and more beautiful relations between the phenomenon of Nature 

 "than it hath entered into the mind of man to conceive." Let not 

 our vanity lead us to believe that because God has deigned to 

 guide our steps a few paces on the road of truth, we are justified 

 in speaking as if He had taken us into intimate companionship, 

 and informed us of all His counsels. 



If I have exposed my views on these subjects to you in an 

 acceptable manner, you will perceive that in minds capable of 

 receiving such impressions, biology can indicate the existence of 

 a creative or directive power, possessing attributes, some of 

 which resemble our own, and controlling operations which we may 

 feebly comprehend. Thus far Natural Theology, and no farther. 



What then is the strict relation of Natural History or biology 

 to that great mass of learning and influence which is commonly 



